The resignation comes amid a probe by the company into alleged improper behavior at the company by employees, though the nature of the behavior is unclear.

Edwards was seen as a possible successor to CEO Mark Parker.

Nike Inc's brand President Trevor Edwards has resigned immediately, the Wall Street Journal reported on Thursday, hours after the world's largest shoe maker said the executive would retire in August.

The Journal said the resignation was announced in an internal memo by Chief Executive Mark Parker that also cited reports Nike had received in recent weeks of "behavior occurring within our organization that do not reflect our core values of inclusivity, respect and empowerment."

Parker did not specify the nature of the complaints or whether they involved Edwards or any other executives, the newspaper added.

The Journal cited a Nike spokesman saying there were no allegations against Edwards.

Reuters could not immediately reach Nike for comment outside regular business hours.

In the memo, Parker said Nike was conducting a review of the company's human-resources systems and practices for elevating internal complaints. "This has been a very difficult time," he wrote, according to the Journal.

Nike on Thursday announced Edwards' retirement and said Elliott Hill, the former president of Nike Geographies, would take over as president of consumer and marketplace.

Mark Parker will remain chief executive and chairman beyond 2020.

The moves come nearly a year after Nike made several changes to its leadership structure and streamlined its business segments to four from six. It also eliminated a quarter of its shoe styles and cut 2 percent of its workforce.

Edwards was in charge of that initiative.

Shares of Nike, which is scheduled to report third-quarter results next Thursday, were up marginally in trading after the bell.